For this concept video to make sense, you have to assume the agency has already snagged an asteroid, enclosed it in what looks like a giant garbage bag and moved it into a stable lunar orbit.

NASA released a concept video about how that might work earlier this year.

In the newly released video we watch two astronauts leave Earth in the Orion spacecraft, travel through space for nine days, and then meet up with the asteroid capture vehicle, carefully docking the two vehicles together.

Using a translation boom (what looks like a long piece of pipe), they move hand over hand from the Orion spacecraft to the asteroid capture vehicle, where the spacewalk tools are stored.

It appears NASA engineers don't expect the astronauts to actually climb aboard the asteroid but rather to just get close enough to grab a few bits of it, double-bag them and then put them in a very important-looking silver suitcase.

Then it's back to Earth, where Orion, the astronauts and the asteroid sample will land safely thanks to three brightly colored parachutes.

For all of this to work, however, NASA first has to find the right space rock.

NASA officials say the ideal candidate would be 20 to 30 feet in length, moving at the relatively slow pace (for an asteroid) of 1.5 miles per second and in an orbit that will take it close to the Earth and moon in the early 2020s.